Objectives: To enhance the specificity of prostate cancer (PCa) detection and reduce unnecessary biopsies in men with prostate-specific antigen (PSA) levels of 2.5 to 4.0 ng/mL, we prospectively evaluated various PSA-based diagnostic parameters.
Methods: This study included 273 consecutive men with serum PSA of 2.5 to 4.0 ng/mL referred for early PCa detection or lower urinary tract symptoms. All men underwent prostate ultrasound and sextant biopsy with two additional transition zone (TZ) biopsies. If the first biopsies were negative, repeated biopsies were performed at 6 weeks. Total PSA, PSA density (PSAD), PSA density of the transition zone (PSA-TZ), free/total PSA ratio (f/t PSA), and PSA velocity (PSAV) were determined, and the sensitivity, specificity, and predictive values of these various parameters were calculated.
Results: Of 273 patients, 207 had histologically confirmed benign prostatic hyperplasia (BPH) and 66 had PCa. f/t PSA and PSA-TZ were the most powerful predictors of PCa, followed by PSA, PSAD, and PSAV. Areas under the receiver operating characteristic curves for f/t PSA and PSA-TZ were 74.9% and 70.1%, respectively. With a 95% sensitivity for PCa detection, an f/t PSA cutoff of 41% and a PSA-TZ cutoff of 0.095 would result in the lowest number of unnecessary biopsies (29.3% and 17.2% specificity for f/t PSA and PSA-TZ, respectively) compared with all other PSA-related parameters evaluated.
Conclusions: Compared with standard total PSA assays, f/t PSA and PSA-TZ significantly enhance the sensitivity and specificity of PCa detection in a referral patient population with a total PSA of 2.5 to 4.0 ng/mL.